The invention relates in general to the construction of drain pipes and in particular to a new and useful method and apparatus for forming drain pipes from plasticizable material.
The invention relates to a method for the manufacture of drain pipes, in particular pipes for the dewatering and degassing of waste dumps, from helically wound thermoplastic strip, in which the plastic strip, after emerging from an extruder or after being heated, and, in any case, being in a plasticized condition, is wound with an inclined winding seam on a winding mandrel and welded in the area of the winding seam.
Drain Pipes for dewatering and degassing are usually made from finished pipe. In that case drainage slits are sawed or milled in the pipe after it has been cooled and hardened. This is an expensive operation and requires expensive equipment. In addition, a considerable amount of material is wasted and additional energy is consumed for sawing or milling. The invention is intended to eliminate these disadvantages.